Shop HEPA type replacement filters for the Alen A350 HEPA Air Purifier. Choose from four filter options: HEPA-Pure for allergy and asthma relief; HEPA-Fresh for increased protection against allergies, asthma, and dust; HEPA-Silver to address allergies and asthma with additional protection against bacteria; and HEPA-OdorCell, with all the benefits of the other three filters plus defense against smoke and pet odors.